A gas turbine engine may include multiple sets of nozzles and associated flow circuits that deliver fuel to various portions of a combustor. Particularly, a fuel control system functions to distribute a fuel flow from one or more fuel sources to the selected nozzle circuits in the gas turbine engine. Generally, the fuel control system includes a metering function that delivers a prescribed amount of total fuel flow to be combusted and a flow divider assembly that distributes the metered flow amongst the various nozzle circuits in a predictable manner.
Conventional flow divider assemblies may have difficulty maintaining a predetermined distribution to the various nozzle circuits, particularly over the full range of metered flow rates and downstream nozzle back pressures associated with engine operating conditions from start to max power. The accuracy of these systems is also often limited by unavoidable variations in nozzle back pressures, on both a unit-to-unit basis and in special cases, such as a nozzle blockage. Shortcomings in the accuracy of the flow dividing function can result in sub-optimal combustor performance. An additional drawback of conventional flow divider assemblies is the accumulation of pressure losses associated with conducting the flow division, particularly at high flow conditions. The resulting larger upstream fuel pressures increase the load on the engine main fuel pump, requiring more power extraction from the engine to run the pump and increasing system fuel temperatures.
Accordingly, it is desirable to provide a fuel control system with a flow divider assembly that provides a reliable and accurate distribution of fuel to combustor nozzles independent of flow rates and pressure variations without creating excessive system pressures. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.